Burner valve



P 1968 c. K. LOVEJCY 3,401,001

BURNER VALVE Filed March 1, 1966 qqz C [6 w [JVVENTOR C 12a ies K. Lox 9'91 AT TORNE Y3 United States Patent 3,401,001 BURNER VALVE Charles K. Lovejoy, 1832 Meredith Drive NW., Atlanta, Ga. 30318 Filed Mar. 1, 1966, Ser. No. 530,847 4 Claims. (Cl. 431344) ABSTRACT OF THE DISCLOSURE This invention relates to a burner valve construction for gas fuel lighters that has a flame height adjustment wheel that is mounted on a wick support means, said ad-. justment wheel having an orifice formed therein which communicates directly with the wick. This orifice defines a passage between the wick and an exteriorly positioned closure member that (1) presents a selected surface area of the wick for exposure to the atmosphere when the closure member is opened that insures complete evaporation of the fuel at said surface, said surface area being selected in keeping with the ratio of said exposed surface to the fuel flow rate in said wick means, and (2) limits the volumetric space between the wick and the closure member to prevent initial flare up.

Background of the invention Gas fueled lighters having a reservoir for containing liquid fuel having a low evaporation temperature at atmospheric pressure are well known in the art. For satisfactory performance it has been found that burner valves for such lighters must provide for the evaporation of all of the liquid fuel before it is emitted from the burner outlet for ignition. This is because failure to do so causes erratic ignition and burning of the fuel-air mixture, since any small droplets of liquid fuel remaining within the fuel mixture emitted from the burner outlet will ignite with sudden violent explosions within the major flame of the lighter.

Prior art burner valves have approached the solution of this problem by positioning the evaporation zone at a considerable distance inwardly of the exterior portion of the burner outlet. With the use of the long vaporization zones of prior art gas fueled burner valves, however, a substantial amount of liquid fuel could accumulate within this vaporization zone when the burner outlet was closed and not used for a considerable period of time. On subsequent ignition, this caused a large initial flare-up which produced a hazardous condition.

This invention overcomes problems associated with prior art burners by providing for the evaporation of the liquid fuel substantially in a plane rather than along the length of a passage so that the passage joining the wick and the burner outlet may be extremely short. This eliminates the flare-up normally encountered with previous gas fueled lighters during the ignition thereof, yet prevents the undesirable and erratic burning generally encountered with extremely short vaporization zones.

Summary of the invention The burner valve structure of the present invention includes: (1) a burner stem adapted to be fitted into a lighter casing and having a central passage therein communicating with the reservoir which contains therein liquified gaseous fuel under pressure; (2) a flame height adjustment wheel that is rotatably mounted on the burner stem; (3) a wicking means carried on a supporting anvil positioned between the burner stem and the adjustment wheel so that the flow of fuel may be regulated; (4) an orifice of selected cross-sectional area formed in the adjustment wheel that leads from a portion of the 3,401,001 Patented Sept. 10, 1968 wick adjacent the lower end of said orifice to the atmosphere when open; and (5) an exteriorly positioned manually operable, valve closure member.

The passage which connects the burner outlet with the wick is of such diameter that, at that point adjacent the wick and, for a selected flame height to be produced, the exposed area of the wick is sufficiently large to insure complete evaporation of the fuel at said exposed surface of the wick for the fuel flow rate necessary to maintain the selected flame height. Therefore, given the maximum flame height needed for the burner valve, it may be determined What size burner orifice is required to insure complete evaporation of the liquid fuel at the exposed area of the wick.

These and other features and advantages of the present invention will become more clearly understood upon consideration of the following specification and the accompanying drawings wherein like characters of reference designate corresponding parts throughout.

Brie description of the drawing FIG. 1 is a partially sectioned, elevational view of the upper portion of the gas fueled lighter of the present invention showing the burner valve in sealed position by virtue of the releasable exteriorly positioned closure member being seated on the upper extremity of the burner structure;

FIG. 2 is an enlarged cross-sectional view of the burner valve of FIG. 1; and

FIG. 3 is an enlarged partial cross-sectional view of the burner valve of FIG. 2.

These figures and the following detailed description disclose a specific embodiment of the invention, however, the inventive concept disclosed herein is not limited thereto since the invention may be embodied in other equivalent forms.

Description of the illustrative embodiment Specifically, the burner valve of the present invention is incorporated into a gas fueled lighter construction having a reservoir 10 and the valve assembly is generally designated by numeral 11. The valve assembly 11 includes a burner stem 12 having a central passage 14 extending therethrough along its longitudinal centerline. A flame height adjustment wheel 19 is rotatably mounted on burner stem 12. Extending diametrically across the upper end of the burner stem 12 exteriorly of passage 14 is an anvil 15 having a substantially square cross-section. The lower end of the burner stem 12 which is opposite the end that supports anvil 15 is reduced in diameter to form an engaging portion 16 which is exteriorly threaded so that it may be received in an appropriate aperture A in the upper wall W of the reservoir 10. Intermediate the ends of the burner stem 12 is an exteriorly threaded portion 18 which receives the adjustment wheel 19 thereon in threaded engagement.

Intermediate the threaded portion 18 and the upper end of the burner stem 12 is an annular recess 20 extending around the periphery of the stem 12 which is designed to receive an O-ring sealing means 21 therein.

The adjustment wheel 19 has a cavity 22 formed in its lower side to receive the upper end of the burner stem 12. The lower inner portion of the central cavity 22 is A wick 32 extends between the terminal upper end 25 of the central cavity 22 and the upper surface 34 of the anvil, and its ends hang over either side of the anvil 15 and through the passage 14 to terminate a substantial distance below the engaging portion 16 of the burner stem 12. As is well known in the art, the wick 32 absorbs liquid fuel under pressure and transports this fuel to all parts of the wick 32 including that portion 35 extending between the terminal end 25 of the cavity 22 and the upper surface 34 of the anvil 15.

On the upper exterior surface of the adjustment wheel 19 is an integral raised boss 26 having a gas escape orifice 28 formed therein communicating with the upper end of the cavity 22. The orifice 28 is appropriately located so that the lower end thereof overlies the portion 35 of the wick 32. This allows the compressed wick 32 to expand slightly so that a dome vaporization surface S is formed by the expanded wick 32 exposed by the orifice 28.

Since it is well known in the art that a particular liquified gaseous fuel will evaporate at a particular rate per exposed surface area of the fuel, a determinable rate of evaporation of the fuel will be achieved for the surface S exposed by a particular size orifice 28. Also since a particular fuel flow rate is needed to supply a flame of a particular height, a particular rate of evaporation must take place at the surface S for each desired flame height. Therefore, given a particular flame height to be achieved by the burner valve, the particular size of the orifice 28 can be determined to insure complete evaporation of the fuel at the exposed vaporization surface S.

It will be noted, however, that if the fuel flow rate that will be evaporated at the surface S is exceeded, the pressure within the reservoir will cause an atomized spray containing droplets of liquid fuel to be discharged from the wick 32 through the orifice 28. Since an atomized spray containing droplets of liquid fuel will ignite and burn erratically, the critical ratio of fuel flow rate to exposed surface S is that at which complete evaporation of the liquid fuel takes place at the surface S.

By way of illustration, one such example is set forth below for a one inch flame height. This example utilizes liquified butane as the fuel under a pressure of 35 to 40 psi. in the reservoir 10 at normal room temperature. The wick 32 is a high temperature resistant nylon paper type such as that commercially produced under the trademark Nomex by E. I. du Pont of Wilmington, Del. The thickness of the nylon paper is inch prior to compression and inch during operational compression. The area of the paper held between the terminal end 25 of the cavity 22 and the upper surface 34 of anvil is .100 inch x .060 inch. The orifice 28 is .022 inch in diameter and the fuel flow rate necessary for the one inch flame height is .086 to .090 gram/minute. Using these particular dimensions and materials, complete evaporation of the fuel is accomplished at the exposed vaporization surface S. p

The amount of vaporized fuel" supplied to the gas escape orifice 28 is regulated by selected turning of the adjustment wheel 19 with respect to the burner stem 12 so that the portion 35 of the wick 32 extending between the terminal end of the cavity 22 and the upper surface 34- of the anvil 15 is selectively compressed thereby regulating the compression of the wick 32 so that desired flow of fuel therethrough is achieved. Therefore,

by sizing the gas escape orifice 28"for the maximum flamej 1 height and fuel flow rate needed, th'eburner valve may be? used to satisfactorily produce a flame having any height equal to or less than that for which the orifice 28 is sized. s' The length of orifice 28 in the embodiment given as illustration, is' approximately .070 inch. Therefore, the.

length of orifice to the diameter of the exposed surface S is substantially in the neighborhood of 3. Therefore by 'f restricting the volume of the orifice above surface S, initial flare-up is avoided. 1,7,

The flow of gaseous fuel from the gas escape orifice? 28 is selectively sealed by' gasket G carried in the lnanui'. ally operable cap C that is exteriorly positioned to overliev the boss 26.

It will be obvious to those skilled in the art that many j. variations may be made for the purpose of illustrating the invention without departing from the scope thereof as defined by the appended claims.

I claim:

1. In a gas fueled lighter having a reservoir containing a supply of liquified gaseous fuel therein, a burner valve assembly comprising a wick supporting means, a wick disposed on said wick supporting means and in communication with said fuel supply, a flame height adjustment wheel rotatably mounted for selective adjustment with respect to said wick support means to vary the compression of a portion of said wick and thereby control the rate of flow of fuel therefrom, an orifice formed in said adjustment wheel communicating with said wick, a manually operable exteriorly positioned closure member normally sealing said orifice, said orifice defining a passage that limits the volumetric space between the wick and exteriorly positioned closure member when sealed and exposing a selected surface area of the Wick to the atmosphere when said closure member is open, the ratio of said selected exposed surface area of said wick to said fuel flow rate in said wick being such to insure complete evaporation of the fuel at said exposed surface area and, the length of said orifice beingonly substantially three times the diameter of said evaporation surface, thereby limiting the volumetric space between the evaporator surface and the closure .member to prevent initial flare-up.

2. A burner valve assembly as claimed in claim 1 and. further characterized in that said orifice is within the range of .020 to .030 inch in diameter.

3. A burner valve assembly as claimed in claim 2 and further characterized in that said wick is perature resistance nylon paper. 1 t

4. A burner valve assembly as claimed in claim 3 and further characterized in that the ratio of, exposed surface.

area of the wick in square inches to fuel flow rate in grams per minute is approximately -.006.

. References Cited UNITED STATES PATENTS 3,277,674 10/1966 Kleinet al. 3,327,504 6/1967 Smith.

EDWARD J. MICHAEL, Primary Examiner.

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